Hybrid vehicles incorporating, as motive power sources for traveling of the vehicle, an engine actuating by energy from combustion of fuel and a motor actuating by electric energy, and being provided with an automatic transmission (including a power split device) between the motive power sources and driving wheels, have been put into practical use. In such a hybrid vehicle, traveling based on selective use of the engine and the motor, e.g., in accordance with a driving state, can reduce fuel consumption or emission while maintaining a prescribed traveling performance. Specifically, the vehicle is provided with a plurality of drive modes being different in the actuation state of the engine and the motor, such as the engine traveling mode in which the vehicle travels employing solely the engine as the motive power source, the motor traveling mode in which the vehicle travels employing solely the motor as the motive power source (hereinafter, the motor traveling mode may also be referred to as the EV mode), the engine+motor traveling mode in which the vehicle travels employing both the engine and the motor as the motive power sources. They can automatically be switched in accordance with predetermined mode switching conditions such as a motive power source map employing drive states such as a vehicle speed (or a rotation speed of the motive power sources) and an accelerator pedal operation amount as parameters.
Meanwhile, in such a hybrid vehicle, indication of only the vehicle speed and engine speed as in a conventional engine-driven vehicle employing solely the engine as the motive power source provides only insufficient information for recognizing the actuation state of the motive power sources or the traveling state. For example, indication of the engine speed during the motor traveling mode (which is normally 0) is not helpful. Thus, the driver's need may not always be fully fulfilled.
Harrier Hybrid New Car Model Guide (issued on Mar. 22, 2005 by TOYOTA JIDOSHA KABUSHIKI KAISHA) discloses a combination meter of a hybrid vehicle. The combination meter includes a circular power meter, which is similar to an engine speed meter (tachometer) that indicates the total value of engine output and motor output. The indication range of the power meter is −40˜200 kW, wherein the position (range) of a pointer of the meter lower than 0 means energy recovery.
However, the power meter disclosed in the guide merely shows the output and regeneration state as a hybrid system. Therefore, the driver cannot recognize, for example, how far the accelerator pedal can be pressed down when the vehicle is traveling in the EV mode with the engine stopped, before the engine thereby starts actuation (because it is not possible to satisfy the acceleration request by traveling solely by the motor) (the start of actuation of the engine after activation of the system may also be referred to as “startup”), and how far the brake pedal can be pressed down when the vehicle is traveling (in any mode), before the regenerative braking where energy can be recovered is thereby exited (because it is not possible to satisfy the deceleration request solely by the regenerative braking, or because it is not possible to store the generated power in the battery) the mechanical type brake (hereinafter also referred to as a mechanical brake) starts actuation. As a result, there may be a case where the engine actuates and the fuel efficiency is deteriorated, or a case where the mechanical brake actuates and the energy is not recovered, whereby the fuel efficiency is deteriorated.